Stark structure of the energy spectrum of the Am3+ ion in LaCl3

We have analyzed the structure of the energy spectrum of the Am³⁺ ion in LaCl₃ in the weak and intermediate configuration interaction approximation. We have established that in the intermediate configuration interaction approximation, the mean-square deviation of the calculated values of the Stark level energies from the experimental values is 53% smaller than in the weak configuration interaction approximation. We have determined the even and odd crystal field parameters and the covalency parameters. We conclude that based on analysis of the Stark structure of the energy spectrum, we can make quantitative estimates of the intensity characteristics. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 5, pp. 637–640, September–October, 2006.     

Study of the electric field gradient at <Superscript>111</Superscript>Cd in the <Emphasis Type="Italic">R</Emphasis>Al<Subscript>3</Subscript> compounds synthesized under high pressure

The electric quadrupole interaction parameters for impurity ¹¹¹Cd nuclei in intermetallic RAl₃ compounds (R = La, Ce, Sm, Gd, Tb, Dy, Ho, Er, Yb, or Lu) synthesized under high (8 GPa) pressure at high (1800–1900°C) temperatures have been measured using the method of perturbed angular γγ correlations. It has been established by X-ray diffraction analysis that with an increase in the atomic number of the R element the obtained high-pressure phases are crystallized successively in the orthorhombic, hexagonal, and cubic structures. In the compounds with R = La, Ce, Sm, and Gd, deviation from the known structural types and formation of new ones due to the change in the stoichiometric composition have been observed. The data obtained by the method of perturbed angular γγ correlations have confirmed deviation from the specified stoichiometric composition 1R: 3Al for the LaAl₃, CeAl₃, SmAl₃, and GdAl₃ compounds and verified the correctness of the stoichiometric composition and the presence of the Cu₃Au structural type for the remaining RAl₃ high-pressure phases.     

Influence of alkali promoters on the direction of CO conversion on precipitated Fe catalysts

It has been established that at small conversion degrees of CO on precipitated Fe catalysts the parallel formation of paraffins and olefins takes place. Sodium introduction inhibits the formation of paraffins in the independent direction, which increases the selectivity to olefins.

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, CO . , .

     

Direct amination of 2-methyl-7-chloroceramidonine with ammonia or sodamide

Treatment of 2-methyl-7-chloroceramidonine with aqueous ammonia gives 2-methyl-6-amino-7-chloro-ceramidonine, while treatment with sodamide gives 2-methyl-7-chloro-8-aminoceramidonine.     

Use of acoustic emission to study the breakdown of explosive products

Acoustic emission (AE) was used to investigate the breakdown of products formed from fiber-reinforced explosives under mechanical loading. Acoustic emission was measured during the tensile and compressive testing of the explosives, and with hollow products loaded under internal pressure. Specimens were tested prior to and after being subjected to thermal effects. It was established that breakdown of crystals in the explosive filler provides the basic contribution to the AE effect. It is demonstrated that as for many other materials exhibiting acoustic activity, the Kaiser effect and the effect of a sudden change in AE during crack formation is characteristic of the explosive under investigation. It is also established that the breakdown of hollow products is discontinuous in nature under internal pressure. The results of the investigation suggest the potential of the AE method for investigation of changes in the structure of explosives subsequent to various external effects.Russian Federal Nuclear Center, All-Union Scientific-Research Institute of Experimental Physics, Sarov, Russia. Translated from Mekhanika Kompozitnykh Materialov, Vol. 32, No. 6, pp. 818–823, November–December, 1996.     

Genesis of phase composition in Fe?Mn catalysts for synthesis of olefins from CO and H2 under catalytic conditions in situ

Genesis of the phase composition in oxide Fe–Mn catalysts for olefin synthesis under close to catalytic conditions has been studied in a high temperature X-ray chamber.

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, , Fe–Mn .