Investigation of photochromic cluster systems based on molybdenum oxides by ESR spectroscopy

The electron-spin resonance (ESR) spectra of cluster polyoxometalate systems—a finely dispersed powder of the (NH₄)₆[Mo₇O₂₄]-citrie acid complex, molybdic acid, and molybdenum(VI) oxide—are investigated. The initial samples are colored under exposure to ultraviolet (UV) irradiation (photochromic effect) and thermal annealing. The ESR signal (g _⊥ = 1.94, g _‖ = 1.92) which is observed for the (NH₄)₆[Mo₇O₂₄]-citric acid photocolored samples corresponds to an electron of the molybdenum atom. This is in agreement with the data derived from the electronic spectrum. In addition, the (NH₄)₆[Mo₇O₂₄]-citric acid colored system exhibits an ESR signal (g=2.02) which corresponds to a hole at the organic ligand. This confirms the previously advanced model of intramolecular electron transfer under UV irradiation. The thermally colored molybdic acid has a similar ESR spectrum (g=1.88, 1.92, 1.93, and 1.98). For the other samples, the ESR signal is not observed. It is demonstrated that an unpaired electron of molybdenum atoms is substantially delocalized over all metal atoms in the cluster.     

Dynamics on rugged landscapes of energy and ultrametric diffusion

We discuss the interbasin kinetics approximation for random walk on a complex (rugged) landscape of energy. In this approximation the random walk is described by the system of kinetic equations corresponding to transitions between the local minima of energy. If we approximate the transition rates between the local minima by the Arrhenius formula then the system of kinetic equations will be hierarchical. We discuss for a generic landscape of energy the anzats of interbasin kinetics which is equivalent to the ultrametric diffusion generated by an ultrametric pseudodifferential operator.     

On Minimum Static Breakdown Voltage for a Gasfilled Gap

Russian Physics Journal - Relying on the condition of the discharge self-sustainment, a theoretical analysis is performed aimed at identifying the lowest possible discharge voltage. It is shown...     

Heat capacity of high-purity isotope-enriched germanium-76 in the temperature range of 2–15 K

The heat capacity of high-purity isotopically-enriched germanium Ge-76 has been measured in the range of 2.5–15 K. In this range, the heat capacity of Ge-76 is 6–15% higher than the heat capacity of germanium of the natural isotopic composition, which is determined by a change in the average mass.     

Pseudodifferential <Emphasis Type="Italic">p</Emphasis>-adic vector fields and pseudodifferentiation of a composite <Emphasis Type="Italic">p</Emphasis>-adic function

We discuss transformation of p-adic pseudodifferential operators (in the one-dimensional and multidimensional cases) with respect to p-adic maps which correspond to automorphisms of the tree of balls in the corresponding p-adic spaces. In the dimension one we find a rule of transformation for pseudodifferential operators. In particular we find the formula of pseudodifferentiation of a composite function with respect to the Vladimirov p-adic fractional operator. We describe the frame of wavelets for the group of parabolic automorphisms of the tree T (O _p ) of balls in O _p . In many dimensions we introduce the group of mod p-affine transformations, the family of pseudodifferential operators corresponding to pseudodifferentiation along vector fields on the tree T (O _p ) and obtain a rule of transformation of the introduced pseudodifferential operators with respect to mod p-affine transformations.     

Biology as a Constructive Physics

Yuri Manin’s approach to Zipf’s law (Kolmogorov complexity as energy) is applied to investigation of biological evolution. Model of constructive statistical mechanics where complexity is a contribution to energy is proposed to model genomics. Scaling laws in genomics are discussed in relation to Zipf’s law. This gives a model of Eugene Koonin’s Third Evolutionary Synthesis – physical model which should describe scaling in genomics.     

Andrei Yurievich Khrennikov and his Research

This paper contains a brief review of a very diverse and vast scientific work of Andrei Yurievich Khrennikov on the occasion of his 60th birthday.