Spectral parameter power series analysis of isotropic planarly layered waveguides

This work addresses the analysis of an isotropic planarly layered waveguide consisting of an inhomogeneous core that is enclosed between two homogeneous layers forming the cladding. The analysis relies on an auxiliary one-dimensional spectral problem that is intimately linked with the scalar wave equation for planarly layered media. We construct the Green function of the waveguide as an expansion involving the eigenfunctions of the continuous and the discrete spectrum of the auxiliary problem. From the eigenvalues of the discrete spectrum, we calculate the allowed propagation constants of the guided modes. The Spectral Parameter Power Series (SPPS) method [Math. Method Appl. Sci. 2010;33: 459–468] leads us to analytic expressions for the eigenfunctions of the auxiliary problem in the form of power series of the spectral parameter. In addition, we obtain an SPPS representation for the dispersion relation without making any kind of approximation or discretisation to the core of the waveguide. The SPPS analysis here presented is well suited for its numerical implementation, since all these series can be truncated due to their uniform convergence.     

Investigation of the influence of Zinc-containing compounds on the components of the colloidal phase of milk

To solve the problem of insufficient intake of essential macro - and micronutrients into the human body, particularly in the case of the essential trace element Zinc, the possibility of enriching a socially significant product (milk) with various forms of Zinc is considered. The influence of Zinc-containing compounds on the colloidal milk system's dispersed composition and stability, photon correlation spectroscopy methods, acoustic and electroacoustic spectroscopy was established in this research. It has been shown that Zinc lysinatoriboflavinate, is a colloidal and chelated organic form of the essential trace element Zinc, having the most negligible effects on the composition and stability of the dispersed phase particles. This increases the average hydrodynamic radius of the dispersed phase by 5% and the ζ-potential by 10%.A quantum-chemical simulation of the interaction of milk κ-casein sites with various forms of the essential trace element Zinc in the QChem program was performed using the IQmol molecular editor. The mechanism of action of various forms of Zinc on the components of the dispersed system of milk, in particular milk protein (casein), is suggested.     

[3+2] Annulation of 2-substituted 3-nitro-2H-chromenes with mercaptoacetaldehyde: stereoselective synthesis of tetrahydro-4H-thieno[3,2-c]chromen-3-ols

Chemistry of Heterocyclic Compounds - A diastereoselective method was developed for the synthesis of 4-trifluoromethyl- and 4-phenyl-substituted...     

Controlled crystallization of CaCO(3) on hyperbranched polyglycerol adsorbed to self-assembled monolayers

The formation of biominerals by living organisms is governed by the cooperation of soluble and insoluble macromolecules with peculiar interfacial properties. To date, most of the studies on mineralization processes involve model systems that only account for the existence of one organic matrix and thus disregard the interaction between the soluble and insoluble organic components that is crucial for a better understanding of the processes taking place at the inorganic-organic interface. We have set up a model system composed of a matrix surface, namely, a self-assembled monolayer (SAM), and a soluble component, hyperbranched polyglycerol. The model mineral calcium carbonate displays diverse polymorphism. It could be demonstrated that the phase selection of calcium carbonate is controlled by the cooperative interaction of the SAM and hyperbranched polyglycerol of different molecular weights (M(n) = 500-6000 g/mol) adsorbed to the SAM. Our studies showed that hyperbranched polyglycerol is adsorbed to polar as well as to nonpolar SAMs. This effect can be related to its highly flexible structure and its amphiphilic character. The adsorption of hyperbranched polyglycerol to the SAMs with different surface polarities resulted in the formation of aragonite for alkyl-terminated SAMs and no phase selection for carboxylate-terminated SAMs.     

Spin Transport over Huge Distances in a Magnetized 2D Electron System

Experimental results on the properties of a recently discovered new collective state, the magnetofermionic condensate, are summarized herein. Condensation occurs in a fermionic system, a quantum Hall insulator (filling factor ν = 2), as a result of the formation of a dense ensemble of long‐lived spin cyclotron magnetoexcitons, composite bosons. At temperatures below 1 K, the exciton ensemble exhibits a sharp enhancement in its response to an external electromagnetic field due to the formation of a super‐absorbing state that interacts coherently with the electromagnetic field. Simultaneously, the electrons below the Fermi level rearrange to form a new non‐equilibrium radiative recombination channel. The condensate shows a sharp decrease in viscosity and the ability to spread over macroscopically large distances, on the order of a millimeter, at a speed of $\approx {10}^3\text{cm}{\text{s}}^{?1}$. Due to this rapid long‐distance spin transfer, new opportunities in the field of spintronics have been opened up.     

Chemically induced symmetry breaking in the crystal structure of guanidinium uranyl sulfate

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Synthesis of Novel 5,6‐Dihydropyrrolo[2,1‐a]isoquinolines via Grob Reaction between (E)‐1,1,1‐Trifluoro‐3‐nitro‐2‐butene and 3,4‐Dihydroisoquinolines

Uncatalyzed cycloaddition of 3,4‐dihydroisoquinolines to (E)‐1,1,1‐trifluoro‐3‐nitro‐2‐butene via Grob reaction provide a simple one‐step route to the 5,6‐dihydropyrrolo[2,1‐a]isoquinolines, which represent the basic structural framework of the antitumor active alkaloid crispine.