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Nanocrystals of binary metal tellurides, such as PbTe, Ni2Te3, and Cu7Te5, are synthesized by the polyol method under microwave radiation and studied using X-ray powder diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, and photoacoustic spectroscopy. Binary tellurides are formed only in the case when ethylene glycol is used as a reducing agent and only when the reaction is carried out under microwave radiation. No product is formed when the reactions are performed using a conventional technique of heating. The synthesis of the aforementioned metal tellurides is described, and the proposed mechanism of the reaction is discussed.

We extend the problem of (1 + 1) circular dilaton gravity to include charged particles. We examine the two (charged)-particle case in detail and find an exact equilibrium solution. We then extend this to N-particles and obtain a solution for this case as well. This class of solutions corresponds to N-particles of the same mass, spaced evenly around a circle with charges chosen so that the electric field satisfies E² = constant. We discuss how these solutions are related to the previous uncharged equilibrium solutions and examine the behaviour when the number of particles is large. We comment on the challenges in further generalizing the solutions we obtain.

We extend the problem of (1 + 1) circular dilaton gravity to include charged particles. We examine the two (charged)-particle case in detail and find an exact equilibrium solution. We then extend this to N-particles and obtain a solution for this case as well. This class of solutions corresponds to N-particles of the same mass, spaced evenly around a circle with charges chosen so that the electric field satisfies E2= constant. We discuss how these solutions are related to the previous uncharged equilibrium solutions and examine the behaviour when the number of particles is large. We comment on the challenges in further generalizing the solutions we obtain.

We obtain a new exact equilibrium solution to the N-body problem in 2D gravity. It corresponds to an expanding/contracting circular spacetime with N bodies at equal proper separations from one another around the circle, providing a new class of solutions to further the study of (relativistic) one-dimensional self-gravitating systems. We discuss the relationship of this solution to the single-particle case, as well as the generalizability of our methods to other dilatonic theories of gravity.

Sonochemical and microwave-assisted polyol reduction methods were used to prepare PbSe and PbTe. Products prepared by both methods were compared and analyzed by XRD, EDX, TEM, HR-TEM, elemental analysis, FT-IR, and thermal methods (DSC and TGA). In both methods almost pure lead chalcogenide phases were prepared, which were almost free of carbon (<0.08%), but the morphology of the resultant nanoparticles was entirely different. The mechanism of formation for the lead chalcogenide nanoparticles for both microwave and sonochemical reactions is discussed.

The microwave-assisted polyol reduction method was applied to the preparation of CdSe "nanoballs". The cubic and hexagonal forms of the CdSe nanoparticles obtained were analyzed by XRD, TEM, HRTEM, UV-VIS, photoluminescence (PL) and photoacoustic spectroscopy. Formation of the hexagonal or cubic form of CdSe depends on the glycol used for reaction. It was found that "nanoballs" are built-up of clusters of CdSe with sizes of a few nanometers. A strong blue shift is observed in the absorption spectrum, as expected for size quantization. A possible reaction mechanism is provided.

A new method for the preparation of nanophased tellurides is described. It employs microwave heating for the synthesis of Cu2−xTe and HgTe. The copper telluride prepared by this method was a complex of Cu2−xTe and ethylenediamine, which decomposes into pure Cu2−xTe following annealing at 280°C. A mechanism for the microwave-assisted formation of the tellurides is proposed.

Abstract: This article presents a theory of glass formation based on the mathematical description of agglomeration at the microscopic level. This theoretical model displays a nonnegligible predictive power when applied to the description of the medium-range order in binary covalent glasses such as borates, binary or ternary chalcogenide glasses, and the best known ternary silicon oxide-based glass. The mathematical approach used consists in spotting first the most stable elementary configurations in glass, treated asbuilding blocks, then a careful counting of all types of clusters containing many such entities and evaluation of the number of different pathways leading to their formation. The probabilities of cluster forming are then computed taking into account the multiplicities (statistical factors) and the Boltzmann factors related to the different energetic costs of various agglomeration processes. The probabilities of characteristic features observed in a given glass (e.g., boroxol rings, edge-sharing or vertex-sharing doublets of rings) are then computed; finally, a system of nonlinear equations can be produced by requiring the time derivatives of these probabilities to vanish, which can be interpreted as thesaturation or thestationary regime of the agglomeration process attained at a relatively early stage of glass formation that also corresponds tominimum fluctuations. The most important result of this type of modeling is the correct prediction of the glass transition temperature dependence on modifier concentration.

This article presents a theory of glass formation based on the mathematical description of agglomeration at the microscopic level. This theoretical model displays a nonnegligible predictive power when applied to the description of the medium-range order in binary covalent glasses such as borates, binary or ternary chalcogenide glasses, and the best known ternary silicon oxide-based glass. The mathematical approach used consists in spotting first the most stable elementary configurations in glass, treated asbuilding blocks, then a careful counting of all types of clusters containing many such entities and evaluation of the number of different pathways leading to their formation. The probabilities of cluster forming are then computed taking into account the multiplicities (statistical factors) and the Boltzmann factors related to the different energetic costs of various agglomeration processes. The probabilities of characteristic features observed in a given glass (e.g., boroxol rings, edge-sharing or vertex-sharing doublets of rings) are then computed; finally, a system of nonlinear equations can be produced by requiring the time derivatives of these probabilities to vanish, which can be interpreted as thesaturationor thestationary regimeof the agglomeration process attained at a relatively early stage of glass formation that also corresponds tominimum fluctuations. The most important result of this type of modeling is the correct prediction of the glass transition temperature dependence on modifier concentration.

Let the Lie groups G and H act on the manifold P in such a way that P fibres as a principal G-bundle over P/G and as an H-bundle over P/H. We find that every pair (t',t?) where t' is an H-invariant connection form in P?P/G and t? is a G-invariant connection form in P?P/H corresponds uniquely to a connection form in P?P/(H×G) and a cross-section of a vector bundle with base P/(H×G).

In view of recent experiments we extend our previous growth model for fullerene formation. It becomes clear how a high efficiency of C60 formation is achieved. We estimate the size dependence of intermediate structures along the most efficient growth route and furthermore the stability of Si2o, Ge2o vs. the unstable C20-

We discuss a method of determining the form of the hypothetical gravitational Lagrangianf(R) replacing the Einsteinian LagrangianR in order to avoid the singularity in cosmological solutions. Instead of supposing some form off(R) and then trying to solve the generalized Einstein equations, we treatf(R) as an unknown function while inserting the cosmological solution coinciding with Friedmann solution everywhere except for the singularity, which is replaced by a regular minimum of the scale factora (t) (a regular maximum of curvature). Then we findf(R) by numerical integration. The Lagrangians thus obtained for different cases (k=0, ± 1, and with the equation of state corresponding to pure radiation) have some common properties, among which ¦f(R)¦ < ¦R¦ (concavity), and the absence of asymptotes.

A model of growth of icosahedral capsids is proposed. It is similar to the stochastic model of fullerene growth, but takes into account variations in the composition of pentamers and hexamers that are responsible for the final capsid size. We show that the observed high yield of capsid production implies a high level of self-organization of the elementary building blocks.

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