The Influence of Signal Polarization on Quantum Bit Error Rate for Subcarrier Wave Quantum Key Distribution Protocol

In this paper, we consider the influence of a divergence of polarization of a quantum signal transmitted through an optical fiber channel on the quantum bit error rate of the subcarrier wave quantum key distribution protocol. Firstly, we investigate the dependence of the optical power of the signal on the modulation indices’ difference after the second phase modulation of the signal. Then we consider the Liouville equation with regard to relaxation in order to develop expressions of the dynamics of the Stokes parameters. As a result, we propose a model that describes quantum bit error rate for the subcarrier wave quantum key distribution depending on the characteristics of the optical fiber. Finally, we propose several methods for minimizing quantum bit error rate.     

New Blood Coagulation Factor XIIa Inhibitors: Molecular Modeling,Synthesis, and Experimental Confirmation

In the modern world, complications caused by disorders in the blood coagulation system are found in almost all areas of medicine. Thus, the development of new, more advanced drugs that can prevent pathological conditions without disrupting normal hemostasis is an urgent task. The blood coagulation factor XIIa is one of the most promising therapeutic targets for the development of anticoagulants based on its inhibitors. The initial stage of drug development is directly related to computational methods of searching for a lead compound. In this study, docking followed by quantum chemical calculations was used to search for noncovalent low-molecular-weight factor XIIa inhibitors in a focused library of druglike compounds. As a result of the study, four low-molecular-weight compounds were experimentally confirmed as factor XIIa inhibitors. Selectivity testing revealed that two of the identified factor XIIa inhibitors were selective over the coagulation factors Xa and XIa.     

Characteristics of phase transitions in crystals having a triangular structure in a magnetic field

Analysis of the field dependence of the order parameters and comparison with experimental data on the behavior of the magnetic characteristics of iron phosphide compounds in the stability region of the metamagnetic phase provides a basis for identifying the type of magnetic structure that can exist in this case. The invariants responsible for first-order magnetic phase transitions in crystals having a triangular magnetic structure are identified from the entire rational basis of invariants. Fiz. Tverd. Tela (St. Petersburg) 39, 940–945 (May 1997)     

Ionization and fragmentation of clusters evaporated from the surface of a metal by accelerated ions

A mechanism is proposed for the ionization of clusters evaporated from the surface of a metal subjected to fast-ion bombardment. According to this mechanism, part of the internal energy of the cluster nuclei is transferred to its electronic subsystem, with subsequent ionization. Within the framework of this approach, the dependence of the degree of ionization on n (the number of atoms in the cluster) is calculated for the evaporated clusters. The results obtained are in agreement with experimental data. Zh. Tekh. Fiz. 67, 1–5 (December 1997)     

Structure and Electrosurface Properties of Porous Glasses with Different Compositions in KCl and NaCl Solutions

For porous glasses with and without small amounts of fluorine and phosphorus, structural (specific surface area, structure resistance coefficient, and mean pore radius) and electrosurface characteristics (adsorption of potential-determining ions, conductivity, counterion transport numbers, and electrokinetic potential) in sodium and potassium chloride solutions are compared. Results of measuring the equilibrium and transport characteristics of membranes are used to calculate the constants of surface reactions and adsorption potentials of ions within the framework of the 2-pK model of oxide surface charging. Within the framework of the homogeneous model, electrochemical characteristics of porous glasses, namely, concentrations of co- and counterions in a pore-confined liquid, Donnan potentials, convective component of the conductivity of a pore-confined solution, and mobility of counterions in the membranes, are calculated.__________Translated from Kolloidnyi Zhurnal, Vol. 67, No. 3, 2005, pp. 342–351.Original Russian Text Copyright © 2005 by Ermakova, Medvedeva, Volkova, Sidorova, Antropova.     

Transformations of unsymmetrical N-hetarylformazans in acidic media

1-Aryl-3-phenyl-5-hetarylformazans undergo acid cleavage to give benzaldehyde hetarylhydrazones, whereas 1-hetaryl-3-phenyl-5-(4-nitrophenyl)formazans undergo acid cleavage to give benzaldehyde 4-nitrophenylhydrazones. 1-Aryl-3-phenyl-5-(6-oxo-4-methyl-2-pyrimidinyl)-formazans undergo cyclization to 1,2,4-triazolo[4,3-a]pyrimidine derivatives.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1268–1270, September, 1977.     

Functional derivatives of thiophene

5-Tosylamino-2,3-dialkylthiophenes, which are alkylated to the corresponding 5-alkyl (tosyl)-amino derivatives, were synthesized from 2-amino-3-carbethoxy-4,5-dialkylthiophenes by tosylation and subsequent decarboxylation.See [1] for communication XV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 204–206, February, 1977.