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The room temperature phosphorescence (RTP) of phenanthrene (PH) was studied before and after oxygen removal in a suspension formed by adding tert-butylbenzene (TBB) to an aqueous solution of PH and β-cyclodextrin (CD). The RTP decay curves indicate that PH molecules are located inside solid aggregates within two types of the self-assembled phosphorescent complexes. The structure of one of them, PH@2CD@2TBB (I), was proposed by the method of fluorescence spectroscopy and confirmed by the quantum-chemical (QC) calculation (PM3/PM6-DH+) indicating the presence of the direct contact between PH and TBB inside the CD dimer in aggregate. The structure of the second, PH@3CD@2TBB (II), was calculated by the QC method. The molecular dynamics simulation (MD) was performed to elucidate the stability in an aqueous solution and in solid matrices of both I and II characterized by different degrees of PH packing density inside the aggregate. Due to the higher stability, I turned out to be the preferred structure as the basis of the phosphorescent center in a solid aggregate. To elucidate the mechanism of RTP quenching the O2 molecules was added to the solution and solid systems of both I and II. Oxygen mobility and penetration statistics to PH in these systems were calculated. Both the fluorescence data and computer simulaions show that the longest-lived component of the RTP decay belongs to structure I, in which PH is sandwiched between two TBB molecules in the CD dimer, owing to which RTP is characterized by the minimum values of the quenching and nonradiative relaxation constants. PH molecules located in a less rigid environment like complex II, or as part of other less ordered structures, are characterized by shorter RTP lifetimes. The results demonstrate a high degree of protection of the substrate encapsulated in the CD dimer from oxygen.

This work is concerned with the specific features of sintering of solid solutions of the PZT system (PbZr 1− x Ti x O 3 , 0.0≤ x ≤1.0) depending on composition. The microstructure of the solid-solution ceramics has been found to be a fairly homogeneous, mosaic, sufficiently close packing of isometric crystallites with a range of section from 3 to 11 μm, but there exists a number of special features related to the component and phase composition of the objects. It has been found that the changes in multifractal parameters of grain structure of these ceramics reflect with high sensitivity the processes of phase transformations in the solid solutions. The obtained results are useful in developing piezoelectric materials based on the PZT system.

The greatest relaxation time for an assembly of three-dimensional rigid rotators in an axially symmetric bistable potential is obtained exactly in terms of continued fractions as a sum of the zero frequency decay functions (averages of the Legendre polynomials) of the system. This is accomplished by studying the entire time evolution of the Green function (transition probability) by expanding the time dependent distribution as a Fourier series and proceeding to the zero frequency limit of the Laplace transform of that distribution. The procedure is entirely analogous to the calculation of the characteristic time of the probability evolution (the integral of the configuration space probability density function with respect to the position co-ordinate) for a particle undergoing translational diffusion in a potential; a concept originally used by Malakhov and Pankratov (Physica A 229 (1996) 109). This procedure allowed them to obtain exact solutions of the Kramers one-dimensional translational escape rate problem for piecewise parabolic potentials. The solution was accomplished by posing the problem in terms of the appropriate Sturm–Liouville equation which could be solved in terms of the parabolic cylinder functions. The method (as applied to rotational problems and posed in terms of recurrence relations for the decay functions, i.e., the Brinkman approach c.f. Blomberg, Physica A 86 (1977) 49, as opposed to the Sturm–Liouville one) demonstrates clearly that the greatest relaxation time unlike the integral relaxation time which is governed by a single decay function (albeit coupled to all the others in non-linear fashion via the underlying recurrence relation) is governed by a sum of decay functions. The method is easily generalized to multidimensional state spaces by matrix continued fraction methods allowing one to treat non-axially symmetric potentials, where the distribution function is governed by two state variables.

An anomalous temperature dependence of carbon fibrils’ electric conductivity in the range of 11–320 K is considered. The fibrils are prepared from polyacrylonitrile by heat-treatment at 1400°C. Our conjecture is that in these carbon fibrils different phases coexist. A heterogeneous model is developed and a good fit to the experimental temperature dependence of the conductivity of our fibrils is obtained.

An anomalous temperature dependence of electric resistivity in carbon fibrils in the range from 11 to 350 K is considered. The fibrils are prepared from the polyacrylonitrile fibrils by heat-treatment. A heterogeneous model of conductivity is developed and a fit to the experimental dependencies of resistivity is obtained. The adequacy of this model to a fibril conductivity problem is explained.

Experimental data related to the impulse photocurrent in emeraldine base (EB) films of various morphology in a wide temperature range are considered. The rate constants for the recombination of the photoinduccd charges are estimated; their dependence on the material morphology is explained. The temperature dependence of photoconductivity is discussed.

A simple kinetic model of photocurrent relaxation in emeraldine base (EB) films is considered. Parameters of a distribution of electrons in traps are evaluated depending on temperature and time after ns-laser excitation. It is shown that carrier traps in EB films are formed by fluctuations of mutual arrangement of polymer fragments.