Novel 1D coordination polymer {Tm(Piv)3}n: Synthesis,structure, magnetic properties and thermal behavior

The new 1D coordination polymer {Tm(Piv)₃}_n (1), where Piv=OOCBu^t?, was synthesized in high yield (>95%) by the reaction of thulium acetate with pivalic acid in air at 100 °С. According to the X-ray diffraction data, the metal atoms in compound 1 are in an octahedral ligand environment unusual for lanthanides. The magnetic and luminescence properties of polymer 1, it’s the solid-phase thermal decomposition in air and under argon, and the thermal behavior in the temperature range of ?50…+50 °С were investigated. The vaporization process of complex 1 was studied by the Knudsen effusion method combined with mass-spectrometric analysis of the gas-phase composition in the temperature range of 570–680 K.     

The influence of nanotubes with various chirality on solvent structure

The structural and dynamic properties of solutions of electrolytes close to single-walled carbon nanotubes was studied by the method of molecular dynamics. The influence of nanotube chirality on the structure of solutions was analyzed.     

Hot-melt adhesives based on polyamides of dimerized fatty acids and adhesive compositions from oligoamidoamines and epoxy resins

The production and the application of hot-melt adhesives and adhesive compositions based on polyamide and the oligoamidoamine derivatives of dimerized fatty acids are studied. The possibility of synthesizing basic polyamide thermoplasts with desired physicochemical properties is shown.     

Industrial Reactor Power Monitoring Using Antineutrino Counts in the DANSS Detector

Detection of antineutrino by the reaction of the inverse β-decay can be used for an independent monitoring of a nuclear reactor power. DANSS detector is located directly under a commercial WWER-1000 reactor and counts up to 5000 antineutrino per day, providing the accuracy of 1.5% in 2 days of the flux measurement. A powerful system of the passive and active shielding in combination with the fine spatial segmentation of the detector allows to diminish the contribution of the background processes to a level, negligible in comparison to the statistical error. The influence of the nuclear fuel composition on the neutrino flux can be accounted for based on the input from the NPP staff.

     

Optimization of MRI parameters for the gradient echo method in fluorocarbon research

The problems of magnetic resonance imaging (MRI) of objects having a very wide spectrum of the nuclear magnetic resonance, where signals from all its lines are difficult to detect, have been investigated. It is proposed to carry out MRI using frequency-selective pulses. A method for setting optimally the pulse parameters and the start time of induction signal detection is described. The calculation results are compared with the MRI data obtained for a fluorocarbon compound.     

Preclassification of Broadband and Sparse Infrared Data by Multiplicative Signal Correction Approach

Preclassification of raw infrared spectra has often been neglected in scientific literature. Separating spectra of low spectral quality, due to low signal-to-noise ratio, presence of artifacts, and low analyte presence, is crucial for accurate model development. Furthermore, it is very important for sparse data, where it becomes challenging to visually inspect spectra of different natures. Hence, a preclassification approach to separate infrared spectra for sparse data is needed. In this study, we propose a preclassification approach based on Multiplicative Signal Correction (MSC). The MSC approach was applied on human and the bovine knee cartilage broadband Fourier Transform Infrared (FTIR) spectra and on a sparse data subset comprising of only seven wavelengths. The goal of the preclassification was to separate spectra with analyte-rich signals (i.e., cartilage) from spectra with analyte-poor (and high-matrix) signals (i.e., water). The human datasets 1 and 2 contained 814 and 815 spectra, while the bovine dataset contained 396 spectra. A pure water spectrum was used as a reference spectrum in the MSC approach. A threshold for the root mean square error (RMSE) was used to separate cartilage from water spectra for broadband and the sparse spectral data. Additionally, standard noise-to-ratio and principle component analysis were applied on broadband spectra. The fully automated MSC preclassification approach, using water as reference spectrum, performed as well as the manual visual inspection. Moreover, it enabled not only separation of cartilage from water spectra in broadband spectral datasets, but also in sparse datasets where manual visual inspection cannot be applied.     

Elastic constants of glass-reinforced plastics with anisotropic structure

The macroscopic elastic constants of plastics reinforced in one direction are calculated by solving the statistical boundary value problem of the theory of elasticity. The results obtained and the method proposed in [15] are used to compute the macromoduli of GRP with an anisotropic layered structure created by an orthogonal arrangement of unidirectional tapes and to compute the moduli of elasticity of a unidirectional layered material with random deviations of the layers from the direction of preferred orientation.V. A. Steklov Mathematical Institute, Academy of Sciences of the USSR, Sverdlovsk Branch. Translated from Mekhanika Polimerov, Vol. 4, No. 4, pp. 631–637, July–August, 1968.     

Influence of intermolecular hydrogen bonding on magnetic properties of mononuclear cobalt and nickel pivalates with amidine ligands

The magnetic properties of the mononuclear cobalt(ii) amidine complex Co(Me₃CCOO)₂{H₂N(C₅H₃N)NH(MeC=NH} (1) having a tetrahedral structure and its solvate 1·HOOCCMe₃·0.5C₆H₆ (1a) are substantially different. Complex 1 possesses ferromagnetic properties and exhibits residual magnetization at liquid-helium temperatures, whereas solvate 1a and the octahedral amidine complex Ni(Me₃CCOO)₂{H₂N(C₅H₃N)NH(MeC=NH}·MeCN (3·MeCN) show antiferromagnetic properties. Apparently, this is associated with the difference in the type of intermolecular nonbonded interactions in the crystals of 1, 1a, and 3·MeCN, which form channels for spin-spin exchange. The tetrahedral isostructural mononuclear complexes ML₂ (M = Co (5), Ni (6), L is N-tosyl-2,5-dimethyl-8-aminoquinoline) were synthesized. These complexes exhibit antiferromagnetic properties.     

Noncatalyzed redistribution reactions of radicals in the series of organogermanium compounds

Conclusions Tetraalkyl(phenyl)germanium reacts with germanium tetrahalides in the absence of catalysts. A method for the synthesis of phenylgermanium trihalides was developed on the basis of this reaction.Deceased.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1663–1664, July, 1976.