Platinum and palladium nanoparticles in modified mesoporous phenol—formaldehyde polymers as hydrogenation catalysts

Mesoporous polymeric supports modified with sulfo groups and PPI dendrimers have been prepared. Catalysts containing palladium and platinum nanoparticles have been synthesized on their basis. The resulting catalysts have been studied by transmission electron microscopy and X-ray photoelectron spectroscopy. It has been shown that the metal deposition procedure has an effect on the morphology of the resulting catalyst. Catalytic activity has been studied using the example of the hydrogenation of phenylacetylene and naphthalene at temperatures of 80 and 400°C, and pressures of 1.0 and 5.0 MPa, respectively.     

Peculiarities of airway processing when tracking air targets observed at small eleveation over underlying surface

The paper considers peculiarities of airway processing of air targets flying rapidly at small elevation angles, with regard for radio wave propagation over the underlying surface, and with high requirements to accuracy and reliability of the route data. The work includes results of simulation permitting to assess effectiveness of the approaches suggested.     

Estimating error of the optimal grid design in the problems of nonlinear optimal control of prescribed duration

Presented was a new grid method for design the feedback-optimal control law (optimal design) in the problem of optimal control of prescribed duration. The difference between the optimal result and the result of control based on the proposed grid design was estimated for any initial state of the controlled system. These estimates were illustrated by the solutions of nonlinear model problems of control on plane where the graph of the cost function (optimal result) at the given time instant is compared with the graph of the results of control using the proposed construction.     

Defining the asymptotics for one class of singularly perturbed problems of vibrational mechanics

In this paper, a solution algorithm for the optimal control problem for the system with uncertain dynamics which is the asymptotics of the singularly perturbed system with fast oscillator is proposed.     

Optical and photosensitive properties of comb-shaped polyamide-imides

A new method for modifying polymers with side carboxyl groups by glycidyl ethers of hydroxyl-containing azobenzene dyes has been developed. The spectral, thermomechanical, and photosensitive properties of dye-modified polyamide-imides have been studied as a function of the dye content in a polymer. The films of polymers under study were shown to be almost transparent at wavelengths above 500 nm. The mobility of side chromophore groups is rather high, which makes these polymers promising for nonlinear optical applications. The polymers are characterized by a photosensitivity of 10³–10⁴ cm² J^?1, which can be significantly increased by doping with diphenylamide molecules, which transport charge carriers.