Rearrangement of the Binuclear K4Mo2Cl8 Cluster Structure in the Process of Its Oxidation in HCl Solution

Russian Journal of General Chemistry - Batch-type spectroscopic and continuous potentiometric titration of K4Mo2Cl8 with potassium dichromate in 1 M hydrochloric acid was carried out. Intermediate...     

In honor of the sixtieth birthday of M. I. Yadrenko,corresponding member of the Academy of Sciences of Ukraine

In honor of the sixtieth birthday of M. I. Yadrenko, corresponding member of the Academy of Sciences of Ukraine     

Absence of Critical Points for a Class of Quantum Hierarchical Models

Hierarchical models of quantum anharmonic oscillators with a polynomial anharmonicity and interaction decaying as (distance)^-1-λ are considered. For a class of such models (including ϕ⁴-type anharmonicity ones), it is shown that the critical fluctuations of the position operator are absent, for all λ > 0 and all temperatures, provided the oscillators mass in less than some threshold value depending on the anharmonicity parameters. This result may be interpreted as a rigorous mathematical justification of physical arguments showing that quantum fluctuations can damp phase transitions. Received: 12 April 1996 / Accepted: 25 October 1996     

Measurement of Dispersion Characteristics of Integrated Optical Microresonators and Generation of Coherent Optical Frequency Combs

Journal of Experimental and Theoretical Physics - Optical frequency combs are a unique tool for fundamental metrology, spectroscopy, and a broad spectrum of applications. High-Q microresonators...     

Second-order semilinear elliptic inequalities in exterior domains

We study the problem of existence and nonexistence of positive solutions of the semilinear elliptic inequalities in divergence form with measurable coefficients in exterior domains in . For W(x)?|x|^−σ at infinity we compute the critical line on the plane (p,σ), which separates the domains of existence and nonexistence, and reveal the class of potentials V that preserves the critical line. Example are provided showing that the class of potentials is maximal possible, in certain sense. The case of (p,σ) on the critical line has also been studied.     

Peierls Argument and Long-Range Order Behavior of Quantum Lattice Systems with Unbounded Spins

Results on long-range order behavior are obtained for systems in arbitrary dimension (v2) with a wide class of spin–spin long-range interactions, without assuming the reflection positivity property.     

Analyse de metaux rares et de materiaux semi-conducteurs a l'aide de l'activation aux helions-3 et aux neutrons thermiques

Résumé On a présenté les méthodes de détermination de O et C dans quelques métaux réfractaires et matériaux semi-conducteurs. On a porté une attention particulière au procédé de traitement de la surface avant et après irradiation et aux méthodes pour séparer du fluor et du carbone radiochimiquement purs. Pour la détermination de Cu, Mn, Co, Ni, Cu et Zn, on concentre les impuretés et on les sépare par la méthode de chromatographie d'extraction. On a discuté des perspectives d'utilisation de la chromatographie d'extraction en analyse par activation des matériaux de haute pureté.     

Regulation Mechanisms in Spatial Stochastic Development Models

The aim of this paper is to analyze different regulation mechanisms in spatial continuous stochastic development models. We describe the density behavior for models with global mortality and local establishment rates. We prove that the local self-regulation via a competition mechanism (density dependent mortality) may suppress a unbounded growth of the averaged density if the competition kernel is superstable.     

A Critical Phenomenon for Sublinear Elliptic Equations in Cone-Like Domains

The authors of this paper study positive supersolutions to theelliptic equation -u = c|x|^–su^p in Cone-like domains ofR^N (N 2), where p, s R and c > 0. They prove that in thesublinear case p < 1 there exists a critical exponent p_*> 1 such that the equation has a positive supersolution ifand only if – < p < p_*. The value of p_* is determinedexplicitly by s and the geometry of the cone. 2000 MathematicsSubject Classification 35J60 (primary), 35B05, 35R45 (secondary).