Wide-aperture cathodoluminescent light source based on an open discharge

The feasibility of an effective high-luminance light source based on an open discharge is considered. Experimental data for the light characteristics of different cathodoluminescent screens are presented. Phosphor coatings are excited by an electron beam initiated by a planar cathode-grid injector in an inert gas atmosphere. The feasibility of maintaining an open discharge using continuous or pulsed-periodic excitation of the gas medium in the light emitter is discussed. The use of the specular method to excite the phosphor coating of the screen makes it possible to achieve a higher luminance and a higher luminous efficacy in comparison with these characteristics for cathodophosphors. The design of the cathode-grid unit allows for a large surface area of the electron injector, making it promising for wide-aperture light sources.     

Thermal decomposition of bis[carbonyl(μ-alkyl(aryl)thio)η5-cyclopentadienyliron] complexes

Conclusion The thermal decomposition of [FeCp(SR)CO]₂ complexes, where B is Et or Ph, leads to ferrocene and a mononuclear complex, FeCpSE(SO)₂. Stable polynuclear complexes are not formed.Deceased.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 655–657, March, 1987.     

Mössbauer study of thermal decomposition of the [FeCp(SPh)CO]2 complex and its reaction with the surface of activated silica gel

Thermal decomposition of the [FeCp(SPh)CO]₂ complex and its reaction with the surface of activated silica gel were investigated by Mössbauer spectroscopy. A small amount of a complex with properties similar to ferrocene is separated in the first stage of thermal decomposition (120–130°C). The starting carbonyl complex totally disappears in the second stage (165–210°C), and two compounds are present among the products: a derivative of ferrocene and the final product, an x-ray amorphous, iron-containing structure with an ionic-covalent type of chemical bond (CB) and a 25 and 5 wt. % concentration of oxygen and sulfur, respectively. The Mössbauer parameters of this product and the compound formed in the reaction of [FeCp(SPh)CO]₂ with the surface of activated silica gel at 4.2–300 K are identical. The analysis of the data suggested that both structures are highly disperse clusters of iron oxide with the structure of an inverted spinel with superparamagnetic properties.Deceased.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 771–778, April, 1991.We would like to thank Yu. B. Kopylovskii for assistance in processing the spectra with the MESLIN program.     

Breakup of Universality in the Generalized Spinodal Nucleation Theory

The problem of nucleation near spinodal is revisited. It is shown that the standard scaling argument due to Unger and Klein [Phys. Rev. B 29:2698–2708 (1984)] based on neglecting all but the first two terms of the Taylor expansion of the potential in the free energy functional is only valid below critical dimension. At critical dimension, the nucleating droplet has a bigger amplitude and a smaller spatial extent than predicted by the standard scaling argument. In this case the structure of the droplet is determined in a nontrivial fashion by the next order term in the expansion of the potential. Above critical dimension, the amplitude of the nucleating droplet turns out to be too big to justify expanding the potential in Taylor series, and no universality is to be expected in the shape and size of the droplet. Both at and above critical dimension, however, the free energy barrier remains finite, which indicates that the nucleation rate does not vanish at spinodal as predicted by the standard scaling argument.     

Front propagation in infinite cylinders. II. The sharp reaction zone limit

This paper applies the variational approach developed in part I of this work [22] to a singular limit of reaction–diffusion–advection equations which arise in combustion modeling. We first establish existence, uniqueness, monotonicity, asymptotic decay, and the associated free boundary problem for special traveling wave solutions which are minimizers of the considered variational problem in the singular limit. We then show that the speed of the minimizers of the approximating problems converges to the speed of the minimizer of the singular limit. Also, after an appropriate translation the minimizers of the approximating problems converge strongly on compacts to the minimizer of the singular limit. In addition, we obtain matching upper and lower bounds for the speed of the minimizers in the singular limit in terms of a certain area-type functional for small curvatures of the free boundary. The conclusions of the analysis are illustrated by a number of numerical examples.     

Synthesis of the first unsymmetrical 34-electron cationic cobalt-nickel triple-decker complex with a central cyclopentadienyl ligand [(η-C6Me6)Co(μ-η:η-C5H5)Ni(η-C5H5)]PF6

The first unsymmetrical 34-electron cationic cobalt-nickel triple-decker complex with a central cyclopentadienyl ligand [(η-C₆Me₆)Co(μ-η:η-C₅H₅)Ni(η-C₅)PF₆ was prepared by the reaction of [(η-C₆Me₆)₂Co]PF₆ with nickelocene. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 798–799, April, 1999.     

Almost-Everywhere Convergence and (o)-Convergence in Rings of Measurable Operators Associated with a Finite von Neumann Algebra

We study the relationship between (o)-convergence and almost-everywhere convergence in the Hermite part of the ring of unbounded measurable operators associated with a finite von Neumann algebra. In particular, we prove a theorem according to which (o)-convergence and almost-everywhere convergence are equivalent if and only if the von Neumann algebra is of the type I.