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R.Z. Mehdiyeva Mir Hasan Yu. Seyidov I.B. Baykulov 《Journal of Physics and Chemistry of Solids》2006,67(12):2623-2627
Boundaries of morphotropic phase transitions region in the system of solid solutions K2Pb4Nb10O30-Na2Pb4Nb10O30-K6W4Nb6O30 with the structure of the tetragonal tungsten bronze have been specified. Presence of the second morphotropic phase transition, perpendicular to the first one has been revealed. The temperature dependences of the structural parameters of some compounds have been investigated. The compounds with high values of Curie temperatures and working temperatures have been obtained. 相似文献
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A. M. Magerramov M. R. Bairamov G. M. Mehdiyeva M. A. Agaeva 《Polymer Science Series B》2012,54(7-8):399-406
Aminomethylated derivatives 2-propenyl-, 2-allyl-, and 4-isopropenylphenols are studied as comonomers in free-radical copolymerization with styrene in bulk. As evidenced by NMR studies, in o-aminomethyl derivatives of alkenylphenols, stable intramolecular hydrogen bonds form between nitrogen atom of the aminomethyl fragment and hydrogen atom of the hydroxyl group; these bonds are not destroyed up to 80°C Therefore, these compounds may be involved in free-radical copolymerization with styrene in which the inhibiting effect of OH groups is avoided at a temperature of 60°C. The values of r 1 and r 2 are determined for two pairs of comonomers: 6-morpholinomethyl-2-propenylphenol and styrene (r 1 = 0.20 ± 0.01 and r 2 = 2.40 ± 0.04) and 2-allyl-6-morpholinomethylphenol and styrene (r 1 = 0.090 ± 0.009 and r 2 = 2.40 ± 0.04). 相似文献
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E. B. Asgerov D. I. Ismailov R. N. Mehdiyeva S. H. Jabarov M. N. Mirzayev E. M. Kerimova N. T. Dang 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2018,12(4):688-691
Triple compounds with the formulas TlFeS2 and TlFeSe2 and magnetic properties are investigated via X-ray diffraction, differential-thermal, and thermogravimetric analyses. Their crystal structures are found. It is ascertained that they are described by monoclinic space group C2/m under normal conditions. The atomic coordinates and interatomic distances are determined. From differential-thermal and thermogravimetric analyses performed at temperatures of 30–900°C, it is revealed that stronger covalent bonds are implemented in TlFeS2 crystals than in TlFeSe2 compounds. The effects associated with energy exchange in the compounds under study are observed. The physical nature of the observed effects is discussed. 相似文献
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Russian Journal of Applied Chemistry - A series of 1,3-benzoxazine derivatives were prepared by ternary Mannich condensation of 2-propenylphenol, formaldehyde, and primary amines (aniline,... 相似文献
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M. N. Mirzayev R. N. Mehdiyeva Kh. F. Mammadov S. H. Jabarov E. B. Asgerov 《Physics of Particles and Nuclei Letters》2018,15(6):673-677
The DSC, TG, DTA, and DTG analyses of boron silicides, which are widely applied in radiation material science and nuclear technology, have been performed depending on the thermal treatment rate. The kinetic parameters (energy, enthalpy, oxidation reaction rate, heat capacity, and activation energy) of effects occurring in the thermal treatment of boron silicides of 99.5% purity within a temperature range of 25–900°C at a rate of 5–20°C/min have been established. It has been established that the phase transition typical for silicides with its central peak at a temperature 572 ± 5°C can exist in boron silicides depending on the thermal treatment rate. In TG and DTG spectra, this appears as an oxidation thermal effect at T ≥ 660°C with a change increase in mass of nearly 9%. 相似文献
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Bayramov M. R. Askarova G. M. Mehdiyeva G. M. Agayeva M. A. Mammadov I. G. Mammadova P. Sh. Jafarzadeh S. H. 《Russian Journal of Applied Chemistry》2020,93(11):1638-1645
Russian Journal of Applied Chemistry - A series of polyfunctional organic compounds, 1-propenyl- and 1-allyl-2-propargyloxy-3-aminomethylbenzenes containing simultaneously an aminomethyl group and... 相似文献
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A COUPLED FLUID-STRUCTURE ANALYSIS FOR 3-D INVISCID FLUTTER OF IV STANDARD CONFIGURATION 总被引:1,自引:0,他引:1
V. GNESINR. RZ?DKOWSKI 《Journal of sound and vibration》2002,251(2):315-327
A three-dimensional non-linear time-marching method and numerical analysis for aeroelastic behaviour of an oscillating blade row is presented. The approach is based on the solution of the coupled fluid-structure problem in which the aerodynamic and structural equations are integrated simultaneously in time. In this formulation of a coupled problem, the interblade phase angle at which a stability (or instability) would occur is a part of the solution. The ideal gas flow through multiple interblade passage (with periodicity on the whole annulus) is described by the unsteady Euler equations in the form of conservative laws, which are integrated by use of the explicit monotonic second order accurate Godunov-Kolgan volume scheme and a moving hybrid H-H (or H-O) grid. The structure analysis uses the modal approach and 3-D finite element model of the blade. The blade motion is assumed to be a linear combination of modes shapes with the modal coefficients depending on time. The influence of the natural frequencies on the aerodynamic coefficient and aeroelastic coupled oscillations for the Fourth Standard Configuration is shown. The stability (instability) areas for the modes are obtained. It has been shown that interaction between modes plays an important role in the aeroelastic blade response. This interaction has an essentially non-linear character and leads to blade limit cycle oscillations. 相似文献
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75As NQR and high-field NMR experiments have been performed on GexAsySe1−x−y glasses. Evolution of As bonding structure from arsenic sites with axially symmetric distribution of the electric field gradient (EFG) to highly asymmetric As surroundings has been revealed. Arsenic atoms form pyramidal structural units in Ge2As2Se7 with no evidence of significant concentration of homopolar bonds. In Ge2As2Se5 most of arsenic atoms form structural units with two As-As bonds per atom and asymmetric EFG distribution. Arsenic bondings become more complicated in Ge0.33As0.12Se0.55 where all arsenic sites are highly distorted. The combination of NQR and NMR data provide valuable information on arsenic bonding dynamics in these glasses. 相似文献
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