Calorimetric and x-ray diffraction studies of the (NH4)3WO3F3 and (NH4)3TiOF5 perovskite-like oxyfluorides

The heat capacity and unit cell parameters of the (NH₄)₃WO₃F₃ and (NH₄)₃TiOF₅ perovskite-like oxyfluorides were measured in the temperature interval from 80 to 300 K; the existence of two and one phase transitions in these compounds, respectively, was demonstrated, and their thermodynamic parameters were determined. The effect of a hydrostatic pressure of up to 0.5 GPa on the phase transition temperatures was studied. Triple points and high-pressure phases were found in the T vs. p diagrams. An analysis of entropy changes suggests that all the structural transformations revealed are associated with the ordering of structural blocks. __________ Translated from Fizika Tverdogo Tela, Vol. 46, No. 5, 2004, pp. 888–894. Original Russian Text Copyright ? 2004 by Flerov, Gorev, Fokina, Bovina, Laptash.     

Interaction of Langmuir solitary waves with electrons of a plama

Interaction of Langmuir solitary waves with superthermal electrons of a plasma is considered. The number of solitary waves per unit length N is assumed to be small, therefore interaction of solitary waves with each other may be neglected. The initial phase of the process of relaxation of the electron distribution function is considered numerically. Continuous generation of accelerated elctrons up to velocities larger than thermal electron velocities is obtained.     

Thermodynamic properties of the mixed elpasolites Rb2KGaxSc1−x F6 (x=0.6–1.0)

Measurements of the heat capacity of the elpasolite Rb₂KGaF₆ and the solid solutions Rb₂KGa_xSc_1−x F₆ with a gallium content in the range x=0.6–0.95 are performed. The nature of the influence of the chemical composition of the compounds and the hydrostatic pressure on the temperature and entropy of the ferroelastic phase transitions is established. Fiz. Tverd. Tela (St. Petersburg) 39, 1844–1849 (October 1997)     

Study of effectiveness of adaptive processing of hf radio signals using three-element receiving antennas

Space processing of hf signals for the elimination of interference and fading is investigated. Working prototypes of an adaptive antenna system consisting of electric dipoles and magnetic loops are described, as are the results of full-scale experiments in the elimination of interference distributed through space and in polarization with the desired-signal source. The possibility of a increase of up to 20–30 dB in the signal-to-noise ratio, which is achieved using a compact antenna system, is demonstrated experimentally.Scientific-Industrial Enterprise Flight. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 36, No. 11, pp. 1032–1042, November, 1993.     

Specific Heat and Thermal Expansion of Triglycine Sulfate–Porous Glass Nanocomposites

The effect of restricted geometry on specific heat capacity and thermal expansion of the triglycine sulfate (TGS)–borosilicate glass composites have been studied first. A decrease in the entropy and temperature of the P2₁ ? P2₁/m phase transition in the TGS component with decreasing the glass matrix pore diameter at the invariable specific heat and thermal expansion coefficient has been observed. The estimates are indicative of the minor effect of internal pressure on the TGS pressure coefficient dT_C/dp in the composites.     

Structural,Magnetic, and Thermodynamic Properties of Ordered and Disordered Cobaltite Gd0.1Sr0.9CoO3 – δ

Journal of Experimental and Theoretical Physics - The effect of cationic and anionic orderings on the crystal structure and magnetic properties of substituted rare-earth cobaltites Gd0.1Sr0.9CoO3...     

Effect of Isovalent Cation Substitution on the Thermal,Caloric, and Magnetocaloric Properties of the (La1 – yEuy)0.7Pb0.3MnO3 Manganites

Physics of the Solid State - Crystalline samples of the (La1 – yEuy)0.7Pb0.3MnO3 (y = 0, 0.2, 0.4, 0.5, 0.6, and 0.8) manganite solid solutions have been grown. Temperature...