On the dynamics of deployment of an orbital structure with elastic elements

The object to be studied is a spacecraft with a deployable pantograph structure as a solar-battery carrier. The objective of research is to design a mathematical model of this structure taking the elasticity of pantograph elements into account. The Lagrangian formalism is followed. To model the dynamic processes in the system, a software package has been developed, which can be adapted, if necessary, to study deployable structures of other types. The behavior of the structure during deployment, collapse, and redeployment under the action of various perturbations is modeled numerically. Plots illustrating the variation of characteristic variables are presented __________ Translated from Prikladnaya Mekhanika, Vol. 42, No. 8, pp. 136–144, August 2006.     

Heat Capacity of Solid Solutions LaLnZr2O7 (Ln = Sm,Gd, Dy) with the Structure of Pyrochlore in the Temperature Range of 10–1400 K

Russian Journal of Physical Chemistry A - Adiabatic and differential scanning calorimetry are used to determine the isobaric heat capacity of LaLnZr2O7 (Ln = Sm, Gd, Dy) solid solutions with...     

A calorimetric study of the thermodynamic properties of potassium molybdate

The low-temperature heat capacity of K₂MoO₄ was measured by adiabatic calorimetry. The smoothed heat capacity values, entropies, reduced Gibbs energies, and enthalpies were calculated over the temperature range 0–330 K. The standard thermodynamic functions determined at 298.15 K were C _p ^° (298.15 K) = 143.1 ± 0.2 J/(mol K), S°(298.15 K) = 199.3 ± 0.4 J/(mol K), H°(298.15 K)-H°(0) = 28.41 ± 0.03 kJ/mol, and Φ°(298.15 K) = 104.0 ± 0.4 J/(mol K). The thermal behavior of potassium molybdate at elevated temperatures was studied by differential scanning calorimetry. The parameters of polymorphic transitions and fusion of potassium molybdate were determined.     

X-ray microanalysis of uranium dioxide particles by using low electron beam energy

The elemental analysis results of the various size uranium dioxide fragments, performed with a scanning electron microscope (SEM) equipped by X-ray energy dispersive analyzer (INCA x-act, “Oxford Instruments”, Great Britain), are presented. The elemental composition calculation was carried out applying the pre-installed program based on the XPP matrix correction algorithm. It is shown that for the bulky UO₂ samples, measured with the varied accelerating voltage in range of 6–20 kV, the uranium concentrations slightly differ (relative uncertainties doesn’t exceed ±2%). The composition of uranium dioxide particles sized up to 0.5 μm can be defined using beam energy of 6 keV with typical for bulky sample accuracy.     

Dynamics of optically induced anisotropy in an ensemble of asymmetric top molecules in the gas phase

A complex theoretical and experimental investigation of the evolution of optically induced anisotropy in an ensemble of free asymmetric tops under collisionless conditions is performed. The dynamics of the orientational correlation functions is studied and the results of femtosecond measurements of the relaxation of the anisotropy of perylene fluorescence in the gas phase are reported. The results obtained are interpreted in terms of the theory developed. It is shown that, in contrast to steady-state anisotropy, the time kinetics of optically induced anisotropy yields more complete and typical data on the dynamics of vector correlations in an ensemble of molecules.     

Cyclization of nitriles 41. Reaction of arylmethylenemalononitriles with malononitrile; crystal structure of 1-amino-3.5-diphenyl-2,4,4,6,6-pentacyano-1-Cyclohexene

1-Amino-3,5-diaryl-2,4,4,6,6-pentacyano-1-cyclohexenes are prepared by reaction of arylmethylenemalononitriles with malononitrile. The cyclohexene ring of (IVa) has a distorted N₂-C¹=C²-C⁷=N¹ fragment. Steric effects in (IVa) cause a substantial increase in C⁶-C¹ and C³-C⁴ bond length to 1.546(4) and 1.570(4) Å, respectively.For previous communication, see [1].Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2771–2775, December, 1989.