Periodic Solutions of a Nonlinear Wave Equation with Nonconstant Coefficients

The existence of time-periodic solutions of a nonlinear equation for forced oscillations of a bounded string is proved when the d'Alembert operator has nonconstant coefficients and the nonlinear term has power-law growth.     

Kinetics of Conversions of Peroxynitrous Acid in Reactions of Isomerization,Decomposition, and Reduction by Cyclohexane

We have studied the kinetics of decomposition and reduction of peroxynitrous acid HOONO by cyclohexane in aqueous solutions. We used the measured effective rate constants of the reactions to compare the reactivities of the acid in the processes of isomerization, decomposition, and reduction.     

Pair production of exotic particles at\mathop p\limits^{( - )} p colliding beams

A maximally complete set of differential cross section has been obtained in Born approximation for pair production of exotic particles with various spinsJ=0,1/2, 1 and quantum numbers (colored and colorless) both inq \(\bar q\) - andgg-collisions. For vector boson processes we systematically use the connection of the unitary of their interaction with gauge invariance, factorization properties of nonabelian gauge amplitudes and the presence of kinematic zeros. Besides, the problem of admissibility of massless limit for these processes is being discussed. The, yields of exotic particle pairs at \(\mathop p\limits^{( - )} \) p colliding beams in TeV energy range have been calculated and limits for the accessible mass range have been found.     

Optical Properties of Binary Mobile Phases as Constituent Objective Functions in Optimizing the Conditions for High-Performance Liquid Chromatography of Hydrophobic Phenol-Like Compounds

The dependence of the absorbance and the UV absorption limits of typical binary mobile phases for high-performance liquid chromatography (HPLC) on the volume fraction of modifiers was analyzed. The applicability of the found relationships to the multiparametric optimization of the mobile-phase composition with a generalized objective function using the Microsoft Excel 2000 spreadsheet program was considered by the example of microcolumn HPLC of hydrophobic phenol-like additives.     

Use of acetonitrile for the extraction of dihydric phenols from salt aqueous solutions followed by HPLC determination

The possibility of using acetonitrile for the extraction of dihydric phenols from water-salt solutions with their further determination by reversed-phase chromatography was studied. The optimal amounts of acetonitrile (10 mL), water (100 mL, pH 2–3) and salting-out agent (NH₄)₂SO₄ (21 g) in the extraction system were determined. The time of determination was 45 min, including sample preparation. The detection limit was 0.005 mg/mL.     

High-voltage electron cooler project for NICA collider

A high-voltage electron cooling system (ECS) with electron energy reaching 2.5 MeV for the NICA collider is being designed at the Joint Institute for Nuclear Research. The ECS is being developed in correspondence with the available experience in manufacturing similar systems from around the world. The main feature of this design is the use of two cooling electron beams (one beam per collider ring); electrons are accelerated and decelerated by a common high-voltage generator. A conceptual project of high-voltage ECS has been developed. The cooler consists of three tanks filled with SF₆ gas under pressure. Two of them contain electron-beam forming systems; each system consists of two electron guns, two electron collectors, and accelerating-decelerating tubes placed in a longitudinal magnetic field generated by a solenoid. The third tank contains a high-voltage generator based on the voltage-multiplying circuit.